One of the major problems with medical or surgical procedures is excessive blood loss or hemorrhage. With the advent of topical hemostatic agents, control of blood loss during these procedures has greatly improved. In general, hemostatic agents provide rapid initiation of a hemostatic plug formed through platelet activation, aggregation, adhesion and gross clot formation. Additionally, ideal hemostatic agents should possess properties such as ease of application, bioresorption, and minimal or no antigenicity.
A wide variety of hemostatic agents are made from different base materials i.e., collagen, gelatin, oxidized regenerated cellulose, fibers, gauze sponges and fibrin. These agents are used in a wide variety of medical and surgical procedures. For example, microfibrillar collagen is used extensively for wide-area parenchyma bleeding and for laparoscopic procedures. Hemostatic sponges are used in surgical as well as dermatological applications where adherence to the wound site and ease of removal are important considerations.
When the damaged tissue is particularly dense (i.e., bone or cartilage), bone waxes are often employed for hemostasis especially where control of bleeding is needed. For example, bone wax is often used to control hemorrhages by closure of intra-osseous vessel canals in cardiac, orthopedic, dental, oral and maxofacial surgery. Typically, bone waxes possess desirable properties i.e., soft, moldable, easy to apply. However, conventional bone waxes interfere with bone healing and are not resorbed by adjacent bone or local surrounding tissues. Bone waxes may also induce inflammatory responses, promote infection and inhibit bone regeneration.
Thus, there is a need for compositions and methods that can easily be delivered to tissue (i.e., bone or cartilage) and control hemostasis or deliver bone growth stimulators (i.e., hydroxyapatite) and/or bone growth factors without delaying or inhibiting bone repair. There is also a need for effective resorbable hemostatic agents that are biodegradable, compatible with bone repair and are easily delivered to the damaged tissue.